.book .book-summary, .book .book-body  {
    font-family: Helvetica, Arial, sans-serif, "Microsoft YaHei UI", "Microsoft Yahei", "PingFang SC", "Lantinghei SC", "Hiragino Sans GB", "WenQuanYi Micro Hei", "WenQuanYi Zen Hei", "Noto Sans CJK SC", "Microsoft JhengHei UI", "Microsoft JhengHei", "PingFang TC", "Lantinghei TC", "Noto Sans CJK TC", "Helvetica Neue";
}

table th {
    min-width: 6em;
}

.markdown-section {
    overflow-x: auto;
}

.markdown-section pre>code {
    font-family: Inconsolata, Consolas, "Microsoft Yahei Mono", "Microsoft Yahei";
}

.markdown-section code {
    font-family: Inconsolata, Consolas, "Microsoft Yahei Mono", "Microsoft Yahei";
}

.tree,
.tree ul {
  margin:0 0 0 1em; /* indentation */
  padding:0;
  list-style:none;
  position:relative;
}

.tree > li:first-child:before {display: none;}
.tree > ul {display: none;}

.tree {margin-left: 0;}

.tree ul {margin-left:.5em} /* (indentation/2) */

.tree ul:before {
  content:"";
  display:block;
  width:0;
  position:absolute;
  top:0;
  bottom:0;
  left:0;
  border-left:1px solid;
}

.tree li {
  margin:0;
  padding:0 1em; /* indentation + .5em */
  line-height:2em; /* default list item's `line-height` */
  position:relative;
}

.tree li:before {
  content:"";
  display:block;
  width:10px; /* same with indentation */
  height:0;
  border-top:1px solid;
  margin-top:-1px; /* border top width */
  position:absolute;
  top:1em; /* (line-height/2) */
  left:0;
}

.tree li:last-child:before {
  background:white; /* same with body background */
  height:auto;
  top:1em; /* (line-height/2) */
  bottom:0;
}

.tree p + ul {
   top: -15px;}
